Millions of buildings around the globe including the Empire State Building and the Eiffel Tower switch off their lights for annual 'Earth Hour' blackout as campaigners urge world leaders to 'save the planet' (15 Pics)

Hundreds off iconic landmarks around the world have been plunged into darkness after they switched off their lights for Earth Hour.

The annual event organised by the World Wildlife Fund is to draw attention to environmental problems and the impact humans are having on the planet.

Buckingham Palace, the Sydney Opera House and the Egyptian Pyramids are among the famous buildings observing the global blackout between 8.30 and 9.30 tonight.

And millions of ordinary households are also expected to turn off their lights to send a message to world leaders who they demand front up to protect the Earth, according to the WWF.

The charity - which asks the question: 'will you switch off for your world this Earth Hour?' -  says that over 10 million people in the UK participated last year.

It says: 'By making pledges to help our planet, and by being part of a movement of hundreds of millions more around the globe, we can show we're fighting for our world.

'We are the first generation to know we are destroying the world. And we could be the last that can do anything about it. We have the solutions, we just need our voices to be heard.'

In the capital, the Shard and the London Eye will observe the blackout while Brighton Pier and Edinburgh Castle are will also go dark.